Which of Newton's laws best explainsq;zoc ;ikf;7hp- /t on why motorists should buckle-up?

  When you sit on a chair, the resultant force on you g(wr/v, wv2 ) wenby2eis

  In the absence of an external for6t 6v0fuai ) a/sknn3bce, a moving object will

  When the rocket engines on the starshi/3f-avny .:c.ti:i fp xwhlz2 p NO-PAIN-NO-GAIN are suddenly turned off, while travelina2 lt.vix- h cf:pw 3zfi/.ny:g in empty space, the starship will

  A rocket moves through empty spa)+euy xd ro *le0pj15j4etp)uce in a straight line with constant speed. It is far from the gravitational effect of any star or planet. Under these conditions, the r)oeyuj4+ ppe j1l)txd50ue*force that must be applied to the rocket in order to sustain its motion is

  You are standing in a moving bus, facing forward, and you sudde )mahcrys (3 lsdjdgj)b-0tw* b,a0 p)nly fall forward. You0 b* )ajlj0drb ah,) -pmdygs3ts()c w can imply from this that the bus's

  You are standing in an56rm 3 3iiq i)qdp/cp moving bus, facing forward, and you suddenly fall forward as the bus comes to an immediate stop. What pi3 p5n6q)iqmci/r3 dforce caused you to fall forward?

  A constant net force acts on an object. Describe the motio ga t*pqomweg c6v6/03n of the object.

  The acceleration of an objecrrd4l, y n2v5 ndxh9(wt is inversely proportional to

  A net force F accelerates a mass m with an acceleration a. If t3lck2fd+s l6 r sg 0o2(jq.chche same net force is applied thr2qs6 sdc2l fc+l 3j(ckg0 .oo mass 2m, then the acceleration will be

  A net force F acts on a mass m and prod+k x q.f/4z8ueseb 5omuces an acceleration a. What acceleration results if a net force 2F act e ekoq b./fux5zsm4+8s on mass 4m?

  If you blow up a balloon, and tcdqzjv r(/l n9d.5arkh8d4l ua-)v.nhen release it, the balloon will fly away. This is an illustration on zva h )dkjln 8l(9q..c/a45-drv durf

  Two cars collide head-on. At every mom8v6d1ep ;j4nh c d,lfient during the collision, the magnitude of the force the first car exerts oj8f1dp4,6 ndlc ;he ivn the second is exactly equal to the magnitude of the force the second car exerts on the first. This is an example of

  If you exert a force F on an object, the forceai( svotd +g,+ which the object exerts on you will(avogd +i st,+

  Action-reaction forcauj dp;(5.5)yh4 kzemalt9o dyun4 +ses

  Action-reaction force mi(kt4w0(r5nr ++pj3ahius1lg/e y js are

  A 20-ton truck collides with a 1500-lb car andog0p(-9r(pm h(ww lqbfx y0r; causes a lot of damage to the car. Since a lot of damage is done r-l(pwom rgq (0(pwx9;bh y0fon the car

  An object of mass m si0azqp7) o o:vits on a flat table. The Earth pulls on this object with force mg, which we will call the action force. Wha)iaqzo :pv07 ot is the reaction force?

  A child's toy is suspended from the ceiling by means of a string. The E7o46mc0y:fwxtdt )a qarth pulls downward on the toy with its weight force of 8.0 N. If this is the "action forcc)fw:dt6t a 4q7o ymx0e," what is the "reaction force"?

  Your bat hits the ball pitched to you with a 1500-N inst0uiaf 9(y nt;ui(q -bl(mrq3r antaneous force. The ball hits the bat with a 3 bu9qrq(f i(n;ra mtl-0u(iyn instantaneous force, whose magnitude is

State Newton's three lawzk *; ,9plmw43u ne(clbsmr:ms.

  Mass and weight

  The acceleration due to gravity is lowku*xrj gidd/3 - n75dzer on the Moon than on Earth. Which of the following is true about the mass and weight of an astronaut on t k7gij/r 35xdn- dudz*he Moon's surface, compared to Earth?

  An example of a force which actsf uk2od(7m(. xmo6chg at a distance is

  Who has a greater weight to mass ratio, a person weig ,k 4(ty t2lql: 2ru-.ncjwbcihing 400 N or a person weighing 600 ( y2,.4luitqjkc rtnl:b w-2cN?

  A stone is thrown straight up. At thlz ;l npi7i0hc6+7zi) e5wqfpe top of its path, the net force acting on it 7ezcip0qzn h7pliil5w;+ f) 6is

  A 20-N weight and a 5.0-N weight are dropped simulnho 3. vp.1jbgtaneously from the same height. Ignore air resistance. Compare theirb1h ..gp vo3jn accelerations.

  A brick and a feather falvda lu*p73g(rs6 beqrg ,q miy,9p-/ol to the earth at their respective terminal velocities. Which object expebmiqar,lvd g /pgqy r*9,3o6up7 e-( sriences the greater force of air friction?

  An object of mass m is hanging by a string from the ceili 4k*v.q*mimqf ng of an elevator. The elevator is moving up at constant speed. What is the t .qm*f*v i4qmkension in the string?

  An object of mass m is hanging by a string from the ceiling of 2q ,vdwo* go4e 7nbbil/xmt ;7:v.wnzan elevator. The elevator is moving upqone7bi :vb4 wntg7;2,o*dv xl/m.zwward, but slowing down. What is the tension in the string?

  The force that keeps you from sli a+ c2l.g 7sxwbxy8z9lding on an icy sidewalk is

  It's more difficult to start moving a heavy 1eq gtqlz,)1 bcarton from rest than it is to keep pushing it with constq,qezbgt1l )1ant velocity, because

  A horizontal force accelerates a box from rest across a horizontal surfa 4ygz3dqb17nd/*1,urwn nc n tce (friction is present) at a constant rate. The experiment is repeated, and all cnz1b3n7*gqc yr nw/t41,nuddonditions remain the same with the exception that the horizontal force is doubled. What happens to the box's acceleration?

  A packing crate slides down an inclins .oc;zluk0y2ed ramp at constant velocity. Thus we can deduce .oklyc0u2;z sthat

  A block of mass M slides down a:u8d gewp.rh5 vffh-; frictionless plane inclined at an angle q with the horiz erd:fp;vhf -. w5uh8gontal. The normal reaction force exerted by the plane on the block is

  A block of mass M slides down a ni lyjq x* tck *,ju9u3i7g+1ofrictionless plane inclined at an angle q with the horizontal. The normal reaction*+u , 3 uxyjktqij1lig 9cn*o7 force exerted by the plane on the block is directed

  A block of mass M slides down a frictionless plahm d kns(/9*wptcyfuz- y/ g08ne inclined at an angle q with the horizonu9(8 */zc dtny0yg/m sp-h kfwtal. The gravitational force is directed

  Two toy cars (16 kg and 2.0*a +6 .ozpacev+cwf 02v5wf dk kg) are released simultaneously on an inclined plane that makes an angle of 30e with the horizontal. Make a statement which best describes their accelerat 6a*pcf0vz+v+wfwad.o ekc 25ion after being released.

  An object sits on a frictionless surface. A 16-N force is applied o-9 s5trx2c3, gjpjon to the object, and ix9 ,j-gr5 s3j otnpoc2t accelerates at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can accelerate from rest to 27 m/s in 7.,cqe ej 6-,m1,ye,w pkp sgsv:0 s. What is the average forwa-ykm:e se,g ejvspp, , 1c6w,qrd force on the car?

  Starting from rest, a 4.0-kg bo9vu1jqyi pj8-yv1 4d ykk(yb;dy reaches a speed of 8.0 m/s in 2.0 s. What is the net force acting onv 9;q-jv4y dpkj1ui 1k8yyy(b the body?

  An antitank weapon fires a 3.00-kg rocket which acquires a s5vc bq 4k (*sf.d4hmo: ;exnrdpeed of 50.0 m/s after traeh s m5d b.4ck(n*:xrq;f4vd oveling
90.0 cm down a launching tube. Assuming the rocket was accelerated uniformly, what is the average force acted on it?

  If you push a 4.0-kg met h/ 9izf9v41tu7dli5uh6 byass with the same force that you push a 10-kg mass from restyhlbdfiuvi u9t5 67e91 4/zth,

  What is the mass of a person who weighs 1)- /j-s6pfsbrmmvk b9lpu/1e10 lb?

  What is the mass of an object that weighs 25smf.6 * kwx1fz0 N on the surface of the Earth where the acceleration due to g1xs*.wmkf z6 fravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. What is the mass of thew;ecf q +;su a2rn6p6p object on the surfs;ae ;+6upwrqc pf 26nace of the Moon where the acceleration due to gravity is only 1/6 of that on the Earth?

  Object A weighs 40 N on Earth, and object B i9i dpsl*,bh *weighs 40 N on the Moon. The Moon's gravity is one sixth of Earth's. Comps*9*i phlidb,are the masses of the objects.

  Sue and Sean are having a tug-of-war by pullivx7hrwp--mvr - p24otng on opposite ends of a 5.0-kg rope. Sue pulls wwx7rp mtp 2--orhv4v- ith a 15-N force. What is Sean's force if the rope accelerates toward Sue at $2.0 \; m/s^2$?

  A stack of books rests on a level frictionless surface. A force F acts te7zswdd8 7nb zf1y nnan7 7+8on the stack, and it accelertz8+nbaf77n7 dy81 ns7ndz weates at $3.0 \; m/s^2$. A 1.0 kg book is then added to the stack. The same force is applied, and now the stack accelerates at $2.0 \; m/s^2$. What was the mass of the original stack?

  A person of weight 480 N stands on a scale in an elevator. What will xng,ije fpoz:,y+18h the scale be reading when the elevator is accelerating downwa h1p,n 8,fj xgo+ie:yzrd at $4.00 \; m/s^2$?

  A person on a scale ridv)mj (irca/ ei;.rs5nes in an elevator. If the mass of the person is 60.0 kg and the elevator accelerates downward with e5/ r(ain.mi; rjvsc) an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale rides in an eagzt 5ncpnl4 r)1tj0)levator. If the mass of the person is 60.0 kg and the elevator accelerates upward with an acceleration o4ztrn lg0jc p15) ta)nf $4.90 \; m/s^2$, what is the reading on the scale?

  Two horizontal forces act on a 5.0-kg mass. One force has a m4453gl)t.ay*+em l p uroe1jtilh p h6agnitude of 8.0 N and is directed due north. The second fol45p1ye4h)u * ojhal eil mpr+g .tt36rce toward the east has a magnitude of 6.0 N. What is the acceleration of the mass?

  An object of mass 6000 kg rests on the flapwph tj6p;;c1us dp2/tbed of a truck. It is held in place by metal brackets that can exert tuhp6jwp;d2; p /scp1a maximum horizontal force of 9000 N. When the truck is traveling 15 m/s, what is the minimum stopping distance if the load is not to slide forward into the cab?

  An object of mass 6000 kg rests on the flat,h r+ib revw)6/:xiepy;g:r cbed of a truck. It is held in place by metal brackets that can exert a maximum horizontal force of 9000 N. When the tr6/e:) v;rpxcierw: ,+ bihyrguck is traveling 15 m/s, what is the minimum stopping time if the load is not to slide forward into the cab?

  In the Atwood machine shown in Fig. 4-1qjdbc0qu1:wmoy ry e(t9 ,2 /s, if M = 0.60 kg and m = 0.40 kg, what is the magnitude of the accey ue,0trc:bo9qd 2m(/jqy1ws leration of the system? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 k6p.sp;v-ic o /m z.a3abl7vpsg and m = 0.40 kg, what is the tension in the string? (Ignore friction and the mass o l.s pomsi; zbp3.6vv7 a/apc-f the pulley.)

  A student pulls a box of books on a smooth hoo : hvczd2(y+u;cmo,arizontal floor with a force of 100 N in a direcd vyo(:2ohcu,mac+z ;tion of $37^{\circ}$ above the horizontal. If the mass of the box and the books is 40.0 kg, what is the acceleration of the box?

  A student pulls a box of books oen7+fge tmo)br yc4+ ix6aqz:n07y e 6n a smooth horizontal floor with a force of 100 N in a direction of 37.0e above the horizontal. If the mass of the box and the booksm ifa67n )e6x7tyz+br+e04 neqcg :o y is 40.0 kg, what is the normal force on the box?

  A traffic light of weight 100 N is suppor qzqt+8z 7aa kbh6n -pe74ccv+ted by two ropes as shown in Fig. 4-2. cqtc ake- 7vq+87hbzn a4zp 6+ What are the tensions in the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 am*j; 1uc(m 9y3gfv+w.v c)l d+ nacxlN, what is the mass of the traff)yaa+c.dlf1ln;*9(uv+ cj3gxm mvwc ic light?

  Two boxes of masses m and 2m are in coyz6vcd+k; acj, 2t rbv .:j.dxntact with each other on a frictionless surface. (See Fig. 4-3.) What ivbk 2t.vxc.rcj6 dyjd+;:z ,a s the acceleration of the more massive box?

  Two boxes of masses ,d( xb:vbhf-x.oszp 1m and 2m are in contact with each other on a frictionless surface. (See Fig. 4-3.) What is thevx,doxs. -z:(bp bh1f net force on the more massive box?

  Two boxes of masses m and 2m are connected by a rope. (See Fig.d:ik 48fqkf vcpa7vtj: 5e5)lk/e4yd 4-4.) If the forward force on the8 4tek7 q p:/dij4c5ydk ve)afv:5klf more massive box is F, what is the tension in the connecting rope?

  Two boxes of masses m and 2m are connected by a rope. (Sekqgm,7*r x5do31w q) txwml b3e Fig. 4-4.) If the forward force on the more massive box is F, whax1ow)7x, wkbqgr* 5 qm 33dtmlt is the acceleration of the less massive box?

Two boxes are connected by 6v)lc dn3wd5pa cord running over a pulley as shown in Fig. 4-5. Box I o3wdnc6 dl5)pvf mass
8.0 kg rest on the top of the table; the coefficient of kinetic friction between box I and the table is 0.10. Box II has a mass of 15.0 kg.
(a) Draw the free-body diagrams for the two boxes, identifying all of the forces acting on each of the masses.
(b) Calculate the acceleration of the system.
(c) Calculate the tension in the cord.

  The coefficient of static and kinetic +p 5 ;kpkisf,sfrictions between a 3.0-kg box and a desk are 0.4pkkp+s; f,i5s 0 and 0.30, respectively. What is the net force on the box when a 15 N horizontal force is applied to the box?

  The coefficients of static and kinetic frictions for plastic on bj0tbh2 hv)h0 *c*vhsn pj50uwood are 0.50 and 0. j*)0*hhbpn0cv 52bhhs jvt u040,
respectively. How much horizontal force would you need to apply to a 3.0 N plastic calculator to start it moving from rest?

  An object slides on a leve,9sae,kt2w2q fsxrwg k0g.r. jv5a.i l surface in the +x direction. It slows and comes to a stop 2igq a xtf.rwjkk5wes.ag, 2,.vr 90s with a constant acceleration of -$2.45 \; m/s^2$. What is the coefficient of kinetic friction between the object and the floor?

  A 10-kg box sitting on a horizontal surface is pulled by a 5.0-N force. dk8 n: 1yahvp )6ugf(x A 3.0-N friction force retards the motion. v )ngfxp6kh:1 yau8d( What is the acceleration of the object?

  A horizontal force of 5.0 N acc-m- b5*mpexrg h .bc)melerates a 4.0-kg mass, from rest, at a rate of $0.50 \; m/s^2$ in the positive direction. What friction force acts on the mass?

  During a hockey game, a puck is given da:19 /kqh g+h:z5e.tgre+hw 2fhxyry se*n4 an initial speed of 10 m/s. It slides 50 m on the ice before it stops. What is thedah w*4r1y.9gt/g:e+ sfh5rnkq h+zxe: e2y h coefficient of kinetic friction between the puck and the ice?

  During the investigatiox e)px t9yuz)- k(sa(zn of a traffic accident, police find skid marks 90.0 m long. They determine the coefficient of friction between the car's tires and the roadway to be 0.500 for the prevailing conditions. Estimate the speed of the car when the brapszt( xy) 9)-a(k zxeukes were applied.

  Two boxes of masses m and 3m are stacked. (See Fig. 4-6.) q ik i(lre00 6/c fn8ltjkzu:+The surface between the more massive box and the horizontal surface is sml+rzik:cleq(nkt6f 8u0 / i 0jooth and the surface between the boxes is rough. If the less massive box does not slide on the more massive box, what is the static friction force on the less massive box?

  Two boxes of masses m an1 x1n1d:xqar2v fwcy;yd jhda z,b5 0/d 3m are stacked. (See Fig. 4-6.) The surface between the more massive box and the horizontal surface is smooth and the surface between the boxes is rough. If the less massive box does not slide dyn511x0:zqdwhxb/fd, c2 aayv;1j r on the more massive box, what is the coefficient of static friction between the boxes?

  An object is on a frictionless inclined plane. The plane is inclined at an angv + :fy bxy4c(c3oqp3ll(y:y 43b3f +pxql vocce of $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down ahx,z2/fw ks ezh077 oa flat hill that makes an angle of $10^{\circ}$ with the horizontal. If friction is negligible, what is the resultant force on the sled?

  A mass is placed on a smooth fibj7 ++ij: 0 x7ys-wy*ugwaa1f m4t2 r*iszkinclined plane with an angle of $37^{\circ}$ to the horizontal. If the inclined plane is 5.0-m long, how long does it take for the mass to reach the bottom of the inclined plane after it is released from rest?

A block lies on a smooth inclined plane tilted at an an4aia 9 kig9/ht3 se8kkgle of $35^{\circ}$ to the horizontal.
(a) Draw the free-body diagram for the block.
(b) Determine the block's acceleration as it slides down the inclined plane.
(c) If the block started from rest 8.5 m up the incline from its base, determine the block's speed when it reaches the bottom of the incline.
(d) How long did it take the block to reach the bottom of the inclined plane?

  A wooden block slides directly down an inclined plane, at a constant v (18,cd ne6bh ,-ehjogiva)tvelocity of 6 (,vt )e1hd 8c-j igobn6eha,v.0 m/s.
What is the coefficient of kinetic friction, if the plane makes an angle of $25^{\circ}$ with the horizontal?

  An object with a mass m slides down a rough mljki/1g(x+uz w-0s /bh*ch l$37^{\circ}$ inclined plane where the coefficient of kinetic friction is 0.20. What is the acceleration of the object?

  An object with a massnp (ssq3p,t p8 eyt4v6 m slides down a rough $37^{\circ}$ inclined plane where the coefficient of kinetic friction is 0.20. If the plane is 10 m long and the mass starts from rest, what will be its speed at the bottom of the plane?

  A bulldozer drags a l 0q)kbkine2ym71tpfqbp /*o43 e2ein og weighing 500 N along a rough surface. The cable attacheeef2pn 04 kepb)k q*/nibyo71i32qt m d to the log makes an angle of $30.0^{\circ}$ with the ground. The coefficient of static friction between the log and the ground is 0.500. What minimum tension is required in the cable in order for the log to begin to move?

A 25.0-kg box is released from rest on a rough inclined plane tiltenx9)k+ / c6u iisngafd3d8p:pd at an angle of9k/n x6pdng +aip3is8:f uc)d $33.5^{\circ}$ to the horizontal. The coefficient of kinetic friction between the box and the inclined plane is 0.200.
(a) Draw the free-body diagram for the box.
(b) Determine the force of kinetic friction acting on the box.
(c) Determine the acceleration of the box as it slides down the inclined plane.

  An object is placed on an inclined plfbb1hwt 0 zunw 2npkdl+t9x+-- e4cn3ane. The angle of incline is gradually increased until the object begins to slide. The angle at which this occurs is q. What is the lbh 1uw d+k4nz3- 2+w0xb9fnptcnt-e coefficient of static friction between the object and the plane?